The internet is full of wild-eyed insinuation. Seemingly accidental events are not actually accidental. A few powerful people have hatched plots to bring about certain outcomes, usually with the goal of benefiting the shadowy string-pullers. As Karl Popper noted in Conjectures and Refutations (1963), some people tend to attribute anything they dislike to the intentional design of a few influential "others." While conspiracy theories have long existed, the internet has accelerated their circulation (like the circulation of all information). Who believes in conspiracies, and what might these people have in common?

There are, of course, differences in the plausibility of any one conspiracy theory. In a 2013 poll, every second U.S. citizen questioned seemed convinced that there was some larger conspiracy at work in the assassination of the president John F Kennedy in 1963, while "only" 4 percent endorsed the notion that "shape-shifting reptilian people control our world by taking on human form and gaining power." (That's still a somewhat unnerving 12 million people.)

Despite these differences, one of the most robust findings in the research on conspiracy theories is that there is a commonality to conspiracy theorists, even if the theories themselves are different. For instance, people who believe in the shape-shifting reptilians are much more likely also to doubt that Lee Harvey Oswald acted as a lone wolf. Indeed, those who believe that Osama bin Laden was dead before the Navy Seals shot him are also more likely to consider it plausible that bin Laden is still alive. This has led many researchers to conclude that the agreement with specific conspiracy theories is not so much dependent on the specific topic, but is rather the manifestation of a more general worldview. The "conspiracist ideation," "monological belief system," or "conspiracy mentality" can be thought of as the general extent to which people see the world as governed by hidden, sinister forces.

Most blame the conspiracy mentality on a sense of profound lack of control in their lives, whether due to randomness or the machinations of others. In one study, research participants who were asked to remember instances over which they had no control, such as the weather, were more likely to accept a conspiracy theory than those who were asked to remember instances in which they did have control (e.g. what they wore or ate). In a similar vein, survey respondents who faced working conditions with reduced levels of control (e.g. long-term unemployment, temporary employment) expressed greater levels of a conspiracy mentality than those who had more control (e.g. permanent employment). The rationale behind this is that lacking control increases the need to engage in the compensatory illusion of control — that is, in conspiracy theories. Detecting patterns where there are none at least leaves open the possibility of gaining control, whereas the attribution of, say, a natural disaster to unchangeable and uncontrollable weather dynamics does not.

While there's something to this, it isn't the full story. This compensatory theory portrays conspiracy theorists as nothing but the poor victims of control deprivation, clinging to conspiracy as the last defense against a chaotic world. This almost stereotypical image, though, is contradicted by the often vocal, evangelizing conduct of actual conspiracy theorists, their claims to superior insight, and their degradation of non-believers as ignorant sheep (German conspiracy theorists label the uninformed masses Schlafschaf, literally "sleepsheep"). What this observation suggests is that adopting a conspiracy belief doesn't always have to be mere compensation for a lack of control but can be instrumental in its own way. Belief in conspiracies can serve to set oneself apart from the ignorant masses — a self-serving boast about one's exclusive knowledge. Adherence to conspiracy theory might not always be the result of some perceived lack of control, but rather a deep-seated need for uniqueness. My research team and I tested this gut hypothesis empirically through a series of studies.

In our first study, the extent to which people described themselves as needing to feel unique corresponded to some extent with their endorsement of specific conspiracy theories. What's more, people who were generally prone to accept a conspiracy theory were more likely to believe theories that were themselves accepted only by a very few people. In other words, those with a conspiracy mentality were more likely to believe less popular theories, perhaps suggesting that the "exclusivity" of the belief is the very commodity they seek.

Of course, correlation does not imply causation (even if they often occur together). Finding that people with a high need for uniqueness tend to endorse conspiracy theories could mean that their need drives them to adopt such theories in order to separate themselves from the naive masses. Or it could mean that believing in conspiracy theories increases the need to feel special and distinct, as a way to distance the self from the ignorant many. And there might be no direct link at all — perhaps people who do not care about what others think exhibit tendencies to set themselves apart from these others and disbelieve what others say. The ultimate litmus test for a causal effect in psychology is an experiment.

So we invented a conspiracy theory from scratch. We asked U.S. participants to read about an entirely fictitious debate unfolding in Germany. The installation of smoke detectors is mandatory according to German housing law (this much is true). Now here comes the fiction: Allegedly, a retired engineer had found evidence that these smoke detectors have serious side effects, emanating a "hypersound" that causes nausea, gastritis, and depression. This was forcefully rejected by VdS Schadenverhütung GmbH, the largest (and invented) producer of smoke detectors. The conspiracy: VdS was in cahoots with the government and knew about the dangerous smoke detectors, but did nothing. Then we introduced the conspiracy as being believed either by a majority (81 percent) or a minority (19 percent) of the German public. Our hypothesis was that those with a higher conspiracy mentality (already correlated with a higher need for uniqueness) were more likely to endorse the conspiracy when finding out that fewer people believed in it than when they found out that many people believed it. And that's exactly what our study showed. The new conspiracy seemed to be more attractive if it was a minority opinion. It set them apart from the masses.

These findings draw a more nuanced understanding of what attracts people to conspiracy theories. Although the effects of our smoke-detector experiment were relatively small, they are consistent. In fact, an independent team from France tested the same hypothesis (without either of our teams being aware) and obtained a very similar result. Seeing evil plots at play behind virtually any world event is not only an effort to make sense of the world. It can also be gratifying in and of itself: It grants one the allure of exclusive knowledge that sets one apart from the sleeping sheep.

This article was originally published byAeon, a digital magazine for ideas and culture. Follow them on Twitter at @aeonmag.